More information: When I use 'dd' to zero out the partition table I get this error afterwards when trying to use pvcreate on the GNBD import: [root@wolverine ~]# pvcreate /dev/gnbd/pool1 Failed to wipe new metadata area /dev/gnbd/pool1: Format-specific setup of physical volume failed. Failed to setup physical volume "/dev/gnbd/pool1" blockdev gives me this error when I try to re-read it after I zero the partition table with'dd' (unmounted, non-gnbd exported): [root@pool-serv1 ~]# blockdev --rereadpt /dev/hdc BLKRRPART: Input/output error I know I'm doing something wrong, but I just can't seem to figure it out. -- Ryan Ryan Thomson (thomsonr@xxxxxxxxxxx) wrote: > > Hello. > > I am currently playing around with the GFS and the cluster tools which I > checked out of CVS on December 3rd. I've created a mock setup using three > cluster nodes, one of which is exporting a disk via GNBD over a private > network to the other two nodes. > > They physical setup looks like this: > > nfs-serv1------| > |----pool-serv1 > nfs-serv2------| > > What I thought I wanted to do was export /dev/hdc from pool-serv1 over GNBD, > import it on one nfs-serv node, use LVM2 to create some logical volumes, mount > it on the other nfs-serv node and then slap GFS over the logical volumes so > both nfs-servers can utilize the same LV concurrently. I either get a "Device > /dev/gnbd/pool1 not found" error or a metadata error depending on the state of > the partition table on the said block device. I get "Device /dev/gnbd/pool1 > not found" when there are no partitions on the disk and I get the metadata > error when I use 'dd' to zero out the partition table. > > I can execute pvcreate on pool-serv1 sometimes, but not others and I can't > figure out under which situations it "works" and which it doesn't exact. > Either way, when it "works", none of the other nodes seem to see the PV, VG or > LGs I create locally on pool-serv1. > > What I've done so far on every node: > > ccsd > cman_tool join > fence_tool join > clvmd > > After those commands, every node seems to join the cluster perfectly. Looking > in /proc/cluster confirms this. > > My /etc/cluster/cluster.conf is as follow: > > <?xml version="1.0"?> > <cluster name="GNBD_SAN_TEST" config_version="1"> > > > <cman> > <multicast addr="224.0.0.1"/> > </cman> > > > <clusternodes> > <clusternode name="wolverine" votes="1"> > <fence> > <method name="single"> > <device name="human" ipaddr="10.1.1.1"/> > </method> > </fence> > > > <multicast addr="224.0.0.1" interface="eth1"/> > </clusternode> > > > <clusternode name="skunk" votes="1"> > <fence> > <method name="single"> > <device name="human" ipaddr="10.1.1.2"/> > </method> > </fence> > <multicast addr="224.0.0.1" interface="eth1"/> > </clusternode> > > <clusternode name="pool-serv1" votes="1"> > <fence> > <method name="single"> > <device name="human" ipaddr="10.1.1.10"/> > </method> > </fence> > <multicast addr="224.0.0.1" interface="eth0"/> > </clusternode> > </clusternodes> > > <fencedevices> > <fencedevice name="human" agent="fence_manual"/> > </fencedevices> > > </cluster> > > I'm thinking this might have something to do with fencing since I've read that > you need to fence GNBD nodes using fence_gnbd but I have no actual foundation > for that assumption. Also, my understanding of fencing is... poor. > > I suppose my major question is this: > > How should I be setting this up? I want the two nfs-servers to both import the > same GNBD export (shared storage), see the same LVs on that GNBD block device > and put GFS on the LVs so both nfs-servers can read/write to the GNBD block > device at the same time. If I'm going about this totally the wrong way, please > advise. > > Any insight would be helpful.